Antiperspirants based on aluminum or aluminum/zirconium salts are known. These materials function as antiperspirants by plugging pores thereby blocking sweat release. Antiperspirant compositions containing aluminum or aluminum-zirconium salts tend to exhibit polymerization of these salts over time, forming species with molecular weights ranging from about 500 to about 500,000 g/mol. In general, lower molecular weight species have greater antiperspirant effect than higher molecular weight species. Without being bound by theory, it is believed that the smaller molecules more readily and more effectively occlude sweat pores, thereby producing the desired antiperspirant effect. Maintaining a relatively low molecular weight and avoiding excessive polymerization enhances the antiperspirant effect and moreover lowers the amount of antiperspirant salt which necessary to control perspiration.
Underarm deodorants control odor by eliminating the bacteria that cause odor. Conventional aluminum or aluminum-zirconium antiperspirant salts tend to be acidic in aqueous solution, a property which makes them effective bacteriocides, thereby providing a deodorant benefit, but which can also cause skin irritation.
Bovine serum albumin (also known as BSA or “Fraction V”) is a serum albumin protein derived from the blood of cattle. It helps maintain the osmotic pressure needed for proper distribution of body fluids between intravascular compartments and body tissues, buffers pH, and acts as a carrier protein for various compounds such as steroids, fatty acids, and thyroid hormones, It is inexpensive, readily available and does not have enzymatic properties, making it useful in many laboratory applications, e.g., to coat plastic materials and prevent adhesion of reactant proteins to the plastic, to stabilize certain enzymes, and to provide a reference standard for protein concentration. The protein has 583 amino acids and a molecular weight of about 66.5 kD. Albumins have been found to contain a high-affinity zinc binding site. See, e.g., J Lu, A. J Stewart, P. J Sadler, T. J. T Pinheiro and C. A Blindauer. “Albumin as a zinc carrier: properties of its high-affinity zinc-binding site”. Biochem. Soc. Trans. (2008) 36, 1317-1321. A. J Stewart, C. A Blindauer, S Berezenko, D Sleep and P. J Sadler. “Interdomain zinc site on human albumin”. PNAS. (2003) 100. No.7. 3701-3706. Albumins such as BSA are not known for use in antiperspirant or deodorant formulations.
There is a need for additional antiperspirant active agents that provide molecular weight complexes of a size capable of plugging pores to block sweat, that provide deodorant/antibacterial efficacy, and that are less irritating to the skin than the acidic salts in conventional antiperspirants.